But there is one point that the Morgan Stanley dealmaker, who is now vice chairman for global wealth management, emphasizes specifically when mentoring women.

"What I say, especially to young women, is, 'Yes do a great job, put the points on the board, make sure that's clear,'" Harris told Business Insider earlier this year.

"But you must as quickly as possible start investing in the relationships around you. Don't just put your head down and work, because you should have a relationship with every seat that touches your seat."

Harris has landed some major deals throughout her 28 years on Wall Street, including the initial public offerings of UPS and Martha Stewart Living.

Harris described two types of "currency" that employees can use in the workplace: performance currency and relationship currency.

"What I've found is that women tend to keep gravitating towards the performance currency, and what happens is, as you get more senior, the relationship currency is the more important currency," Harris said.

The currency is generated by investing in the people in your work environment.

Harris said that as you rise through the ranks in your career, people start to assume that your performance is equal to that of your colleagues. You're less likely to be ranked based on that currency the further you progress.

"What will make the difference for that next big assignment are the relationships that you have," she said.

"Because that next assignment is going to be based on somebody's judgment — judgment about whether or not you're ready, judgment about whether or not you'll be successful, judgment about whether or not the team or whoever else you need will actually follow you — and judgments are directly influenced by relationships."